Coral Cilia Malfunction Highlights Physiological Limits of Reefs
AI-generated image · US National Wire
New research reveals that the microscopic hairs corals use to breathe can actually accelerate suffocation as ocean temperatures rise.
New research into coral physiology suggests that the very mechanisms corals use to survive in low-oxygen environments may fail as oceans warm. According to reporting from Wired, hairlike structures called cilia are essential for coral survival. While corals receive oxygen from symbiotic algae during the day, they rely on cilia at night to generate fast-moving vortices of water that circulate oxygen to their outer tissues.
A study published in Science in May 2026 indicates that as water temperatures increase, the water naturally carries less oxygen. This prompts corals to beat their cilia faster to compensate. However, above a specific temperature, this process becomes counterproductive: the energy required for the furious beating of the cilia consumes the remaining oxygen the tissues can absorb, leading the polyps to suffocate.
This discovery marks a shift from previous scientific understanding. As Wired reports, a 2014 study led by Orr Shapiro—then a postdoctoral fellow at the Massachusetts Institute of Technology and now a researcher at the Volcani Institute in Israel—revealed that corals are not passive recipients of oxygen via diffusion. Instead, they actively create turbulence within the boundary layer of water surrounding them.
Rachel Alderdice, a marine biologist at the University of Konstanz in Germany, notes that these physiological details may explain why some corals bleach while others adjacent to them do not. While scientists have traditionally used symbiotic algae as health indicators, the malfunction of cilia provides a more direct signal of stress and potential mass die-offs.